The features I was most looking forward to were:
1. The use of their POD software on the iPad.
2. Two inputs. One for guitar and one line level input.
When the item arrived, I immediately plugged it into the iPad and noticed that it doesn't really fit really secure. This is a fairly large device and it seems to barely hang into the iPad slot. The second thing I noticed was when I opened the Line 6 POD software that comes free for the iPad, although the sounds were alright (very digital), the latency wasn't too bad in their software but I noticed a lack of input gain control. Some of the dirty sounds didn't push enough. I also own the Apogee Jam and that unit had the ability to control the gain going into the iPad which is nice if your pickups are weaker. So altogether, I wasn't entirely happy with the sounds coming out of Line 6's POD app, so that kind of defeated 1/2 of my purpose for purchase.
Also, the Line 6 app doesn't allow recording or jamming with itunes songs or anything, so unless you only want to use it to jam live, or for practice, all the sounds are not going to do too much else for you.
Latency:
This was the biggest reason for returning the unit. Other than using Line 6's app, Jam Pro, AmpKit Plus and Garage Band all seem to have pretty slow latency. That in combination with the lower input levels made it sub par to the Apogee Jam in comparison.
So, in summary the unit is fine and it does work for all the apps that I tried it with. It does come with two inputs but the lack of volume control and the latency issues prevented me from keeping it. Especially in comparison to the Apogee Jam.
One final note: The Apogee Jam seems to have a more midrange punch designed for guitar. The Line 6 had a more midrange scoop for use on vocals or keys. If you are looking for a unit to record keys and or to use with a mic, the line 6 might be nice. Again, you'd need a preamp to control the input level however. This would entail carrying more gear. I was after a simple solution to bring just my iPad and my guitar.
Hope this review helps someone.
Also, I wish Line 6 would allow us to purchase a version of their app for people without the hardware. I would definitely consider purchasing it for live performance or practice as it did offer a large variety of sounds. Line 6 is leaving cash on the table in my opinion.